Welded ship hull construction



May 1, 1956 J MCALEER 2,743,694

WELDED SHIP HULL CONSTRUCTION Filed Feb. 26, 1952 IN VENTOR UnitedStates Patent WELDED SHIP HULL CUNSTREKIHON John A. McAleer, Weymouth,Mass. Application February 26, 1952, Serial No. 273,436 1 Claim. ((31.114- 79) This invention relates to that class of floating structures inwhich the hull stresses and its resistance to deformation therefrom arecarried by the shell or enveloping plating assisted by seam members ormeans, placed on the inside of all longitudinal plating seams, bothplating and seam reinforcement being in functional relation with rigidframe, open panel transverse girders, in which equilibrium of actionbetween the chords is maintained by moment resisting joints and struts.

One of the objects of this invention is to provide a simple system ofshell support that is light in weight, simple and economical toconstruct and with less than the usual amount of transverse material incontact with the outside shell; thus producing in a Welded or partiallywelded structure a surface of plating freer of contraction wrinkles,lying across the general flow of frictional resistance.

The primary members are initially unstable and of a floating or flexibletype, yet when temporarily spaled or braced they permit the contouringand shaping of a rigid floating structure of any required conformation.To keep the inner chords of the primary stiffeners in their proper shapeuntil the inner seam butt means, which also act as fairing ribbands, andthe shell plating or enough of it, are located in place and welded,these inner chords are pinned down on the slab to shape, in oppositepairs, welded to their common floor bracket and then spaled or braced totheir moulded shape so that they can be used as true permanent moulds ofthe vessels lines. When sufficient plating has been erected and fastenedin place so that the true shape is assured, these temporary spals can beremoved. A transverse strip of the applied plating will then provide thecorresponding flange to the inner chord.

A further advantage of using this rigid open panel transverse frameherein shown, in combination with the reinforced longitudinal platingseams is that this con bination of stiffening creates a semi-monocoqueor stressed skin type of construction in which by controlling the panelsizes of the enveloping shell, the shell can be more uniformly andtherefor more highly stressed than heretofore. The hull will have lesstransverse welding running across the direction of flow and thereforless wrinkling and less tendency to a Euler type of failure throughshell buckling. I am well aware that the combination of light and heavysupport members in all types of structures is not new but my improvementconsists in the combination of a special type of both the heavy and thelight members and their purpose is to produce in a welded or partiallywelded structure not only a structure stronger per pound of metal due toits fairness but economical in labor hours to erect and plate.

The accompanying drawing illustrates the application of the invention tothe shell support of floating structures, the longitudinal inner shellseam straps or butt means being disposed parallel generally to thedirection of travel or motion and the heavier primary frames beingdisposed substantially at right angles thereto.

While the drawing and the specifications might suggest a weldedconnection of the intermediate web mem bers to the enveloping shell, Ido not Wish to limit myself to this as in a particular case it might bepreferable to weld to a riveted clip or to a welded clip, or to aninside transverse doubler, if the functional strip of plating in theouter chord should require it.

The longitudinal butt straps may also be T bars as well as flat bars orother sections that special conditions might demand and the same is alsotrue of the primary stiit'eners and the latter may be canted in the endsso that they may lie more nearly normal to the shell plating.

Referring to the accompanying drawing, showing a portion of such astructure, 1 is a flat plate keel, although such a type of keel is notmandatory, 2 is a center plate keelson and 3 is a center plate keelsonfloor bracket connected to the center keelson by an egg crateconstruction and welded; 4 is the inner chord of a primary transverseframe, connected directly to the longitudinal seam straps 8 and to theshell indirectly by the Web members 5, these web members beingsuiiicient of themselves and by their connections to the inner chord itand to the shell 6 to take the required shear and moment. 6 is the shellplating with its longitudinal scams 8 coming on the longitudinal seambutt straps 7. 10 represents the deck stringer angle andv 9 representswood nailing strips, fastened to the inverted beams 12 so that a wooddeck can be easily applied if required. 11 shows a stanchion placed atthe primary members which also have a. bracket as shown at 13. The deckhouse co-azning plate 15 stiffened by inverted angles 14 and 16represents the top bars of the center vertical keelson 2, both in theusual manner.

Having thus described my invention 1 claim as follows:

A welded hull structure comprising a shell of generally curvilinearcross section, said shell comprising longitudinally extending platemembers, seam Welds extending longitudinally therebetween, angle strapsoverlying and welded to said seam welds, chord members constitutingframe elements positioned within said shell spaced from each other andfrom the shell, the spacing from the shell being greater than the depthof the angle straps, said frame elements extending transversely of theshell, web members positioned perpendicular to the shell and to saidchord members and welded to each and certain of said web members weldedto the angle straps, other of said web members being positionedintermediate said straps and free of attachment thereto whereby saidchord members and said webs form open girders and coact with the slcinto contribute structural rigidity to the hull com- I ponents.

References Cited in the file of this patent UNiTED STATES PATENTS1,029,546 lsherwood June 11, 1912 1,805,669 Liatnin May 19, 19311,923,544 Leonard Aug. 22, 1933 2,058,282 Whitese-ll Oct. 30, 19362,142,945 Kjekstad Jan. 3, 1939 2,644,418 Allegro July 7,, 1953 FOREIGNPATENTS 4,729 Great Britain of 1878

